You want to know about Magento Force HTTPS. Welcome to the MagentDev Blog, the blog of the most famous Magento developers, we will help you set up your Magento site to use HTTPS, but users can still visit your site through non-secure URLs. To force HTTPS on all of the pages on your frontend, please follow these below steps:

Magento Force HTTPS in Magento 1

1. Log in your Magento backend. Go to System > Configuration.2. Under General section, select Web. Then, in the Secure section, change the Base URL to https://yourdomain.com/

3. Change the value of Use Secure URLs in Frontend and Use Secure URLs in Admin options to Yes. Then click Save Config.4. Clear Magento cache. You done forcing Magento 1 HTTPS.